1. Statement of the Technical Field
The present invention relates to the field of facsimile devices and more particularly to processing spam facsimile images in a facsimile device.
2. Description of the Related Art
Second only to the telephone, the facsimile device remains a principal mode of commercial communications. At present, more than eighty-five million facsimile devices have been deployed worldwide and more than one and one-half billion facsimile telephone numbers have been publicly disseminated. Consequently, it should be no surprise that the direct marketing industry has incorporated the facsimile image as a means for mass broadcasting marketing messages in the same way the direct marketing industry has embraced the telephone and electronic mail as a mode of direct advertising.
Historically, the print medium served as the principal mode of unsolicited mass advertising on the part of the direct marketing industry. Typically referred to as “junk mail”, unsolicited print marketing materials could be delivered in bulk to a vast selection of recipients, regardless of whether the recipients requested the marketing materials. With an average response rate of one to two percent, junk mail has been an effective tool in the generation of new sales leads. Nevertheless, recipients of junk mail generally find the practice to be annoying. Additionally, postage for sending junk mail can be expensive for significant “mail drops”. Consequently, the direct marketing industry constantly seeks equally effective, but less expensive modalities for delivering unsolicited marketing materials.
The advent of electronic mail has provided much needed relief for direct marketers as the delivery of electronic mail to a vast number of targeted recipients requires no postage. Moreover, the delivery of unsolicited electronic mail can be an instantaneous exercise and the unsolicited electronic mail can include embedded hyperlinks to product or service information thus facilitating an enhanced response rate for the “mail drop”. Still, as is the case in the realm of print media, unsolicited electronic mail, referred to commonly as “spam”, remains an annoyance to consumers worldwide. As a result, an entire cottage industry of “spam filters” has arisen whose task solely is the eradication of spam.
Like electronic mail, the facsimile medium remains a popular medium for broadcast marketing. Unlike electronic mail, however, there is a real cost to the consumer for receiving spam in the facsimile medium. In particular, a single spam facsimile image can consume paper and toner resource and can consume telecommunications bandwidth which otherwise can be used for sending outgoing facsimiles, or to received legitimate incoming facsimiles. In the United Kingdom, it is estimated that spam in the facsimile domain costs each British company in excess of three-hundred and seventy six pounds annually. In the United States, some estimates place the cost of spam in the facsimile domain at as high as nine-billion dollars per year! So serious and hotly contested has the topic spam fax become, that the State of Missouri successfully sued two of the largest spam faxing organizations under section 227 of the Telephone Consumer Protection Act of 1991 (hereinafter “TCPA”) which suit had been supported by the States of Alaska, Arkansas, California, Colorado, Connecticut, Florida, Idaho, Illinois, Iowa, Kentucky, Maryland, Michigan, Minnesota, New Mexico, Oregon, South Dakota, Texas, Vermont, West Virginia and the District of Columbia. Notably, section 227 of the TCPA makes it unlawful “to send an unsolicited advertisement to a telephone facsimile machine”.
Nevertheless, the outcome of the suit has yet to be resolved and the defendants in suit have called into question the constitutionality of the TCPA in view of commercial free speech protections afforded by the United States Constitution. Additionally, the application of section 227 of the TCPA to Internet fax communications further remains unsettled. In particular, no longer is it required that two telephone facsimile machines coexist to exchange facsimile data. In fact, ITU-T recommendation T.37 specifies the transmission of a facsimile image via the Internet in the absence of telephone facsimile machines.
Notably, spam filters while effective in the electronic mail domain, have no application in the facsimile domain. In particular, electronic mail differs from facsimile images in several distinct and important ways. Most notably, electronic mail can be delivered in a text readable format—typically the MIME format. As a result, spam filters can act directly upon the nature, content and arrangement of text in electronic mail. More particularly, the spam filter can seek out the occurrence of particular words which can indicate the presence of spam. Facsimile images, by comparison, are delivered in rasterized image format whose contents cannot be interpreted beyond mere black and white or color pixels. Thus, electronic mail spam filtering techniques remain ineffective in the facsimile domain and other solutions have been considered alternatively.
Several technologies, though not addressing spam directly, may be viewed as providing rudimentary solutions to the spam fax problem. For instance, in U.S. Pat. No. 5,999,600 to Dong-Myong Shin for FACSIMILE MAIL SYSTEM AND METHOD FOR CONTROLLING THE SAME, a password supplied through DTMF signals can restrict the delivery of a “literal message” where the password provided through DTMF signals does not match a pre-stored password. As another example, in United States Patent Application Publication US 2002/0191226 A1 for CALL-SCREENING DEVICE FOR A FACSIMILE MACHINE, the telephone number of the incoming call can be compared to a database of telephone numbers to determine whether to permit the establishment of a telephonic connection upon which the transmission of fax data can be provided. Interestingly, in U.S. Pat. No. 6,553,494 B1 to Randal Glass for METHOD AND APPARATUS FOR APPLYING AND VERIFYING A BIOMETRIC-BASED DIGITAL SIGNATURE TO AN ELECTRONIC DOCUMENT, biometric data coupled to a document can be used to authenticate the document by a recipient.
In more particular reference to the facsimile domain, several fax specific anti-spam technologies have been marketed. As an example, GFi Software Ltd. has developed the GFI FAXmaker™ line of products in which faxes can be sent and received through ordinary electronic mail clients. As part of the GFI FAXmaker product, a “junk fax filter” is provided through which spam faxes can be “auto-deleted” on the basis of the phone number of the sender of the junk fax. Specifically, a database of phone numbers associated with the sender of a fax identified manually as a junk fax can be used to screen subsequently received faxes.
By comparison, MFM Communication Software, Inc. of Cincinnati, Ohio, United States produces the Fax Everywhere™ product in which manually identified junk faxes can be tagged as “spam”. Once tagged, the contents of the tagged fax can be compared to subsequently received faxes to recognize spam. Where ninety-five percent (95%) of the received fax matches a rasterized image of a stored fax tagged as spam, the received fax can be declared as spam. Thus, the Fax Everywhere product can be viewed as a manually assisted spam fax detection processor which lacks self-learning or pre-emptive spam screening capabilities.
Still, merely comparing a facsimile image to an image stored in a repository of spam fax images can be a resource intensive and time consuming process. More importantly, in a spam detection and blocking system in which spam must be manually identified, the “damage” will have been “done” once the spam has been manually recognized as such—particularly in a high-volume fax environment where a single instance of broadcast spam fax can reach thousands of end users in a single “drop”. Accordingly, it would desirable to dynamically detect spam fax in a self-learning manner without requiring manual intervention.